Add Layer and Artboard node definitions and underlying data structures (#1204)

* Add basic node defenitions

* Code review

* change widget code

* Artboard node changes

---------

Co-authored-by: Keavon Chambers <keavon@keavon.com>

node-graph/gcore/src/vector/vector_data.rs

@@ -17,6 +17,15 @@ pub struct VectorData {
 	pub mirror_angle: Vec<ManipulatorGroupId>,
 }
 
+impl core::hash::Hash for VectorData {
+	fn hash<H: core::hash::Hasher>(&self, state: &mut H) {
+		self.subpaths.hash(state);
+		self.transform.to_cols_array().iter().for_each(|x| x.to_bits().hash(state));
+		self.style.hash(state);
+		self.mirror_angle.hash(state);
+	}
+}
+
 impl VectorData {
 	/// An empty subpath with no data, an identity transform, and a black fill.
 	pub const fn empty() -> Self {